Sounds fine, the only possible issue might be: NM cable and the wire inside
it, is not for use in wet locations. The whip from your switch to the heater
may be considered a wet location. You can use TW or THWN in wet locations



"Wayne Whitney" wrote in message
...
Hello,

I'm planning to run an electrical circuit outdoors for the first time
(with permit and inspections), and I was hoping someone with more
experience could tell me if my plans sound OK. For simplicity I'm
going to run NM cable and sheath it in appropriately sized conduit.

Run 6" RMC nipple through sidewall of crawl space into the back of a
wet locations outlet box. Cap ends with insulating bushings. Makeup
connections, ground the box, and install switch plus wet locations
switch cover with gasket. Run about 2' of NM liquid tight conduit
from the outlet box to the device (exterior tankless water heater),
using liquid tight connectors to make the connections. Makeup the
connections and ground the device. Seal house penetrations and the
outlet plugs for unused ports with 100% silicone.

Sounds OK? Also, a few more assumptions: no locknut is required when
attaching a threaded connector to the threaded ports on the outlet
box. The RMC nipple to outlet box connection should get silicone, as
there is no gasket, and the silicone will not interfere with the
ground bond. Are these assumptions correct?

Thanks, Wayne

P.S. Is RMC identical to iron pipe for water?